


A Lesson in Lust

by mamakostan



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/M, Femdom, Loss of Innocence, Loss of Virginity, Shotacon, Teacher-Student Relationship
Language: English
Status: Completed
Published: 2020-12-04
Updated: 2020-12-04
Packaged: 2021-03-09 22:15:15
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,523
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27883618
Author URL: https://archiveofourown.org/users/mamakostan/pseuds/mamakostan
Summary: (REQUEST) Young Lukas is envious of his teenage peers and their knowledge of more 'adult' topics. In an effort to understand their language better, he turns to his Professor, Byleth.
Relationships: My Unit | Byleth/Original Male Character(s)
Comments: 20
Kudos: 23





	A Lesson in Lust

**Author's Note:**

> hi hi ! this was a fun request, I blazed through it surprisingly quickly ;;

“A new student? This late into the academic year?” Edelgard was conversing with her friend, Dorothea, in the Black Eagles classroom. Their professor had informed them that they would get a new classmate that day. 

“It’s certainly odd, isn’t it? Well, I hope they’re at least cute!” Dorothea flashed Edelgard a flirty wink, eliciting a deep sigh from the princess.

The room was abuzz with whispers of the new student. Before they even had a chance to introduce themselves they were already a spectacle despite Byleth warning her students not to cause a fuss. Unbeknownst to the class, their new classmate would be a young noble boy of only eleven years old. He had excelled in his studies, and thus was to be put in classes with the older students at Garreg Mach. Byleth was aware of this and understood what it felt like to be new to the Monastery, thus she tried her best to calm her students. 

The classroom door creaked open slowly. The entire room snapped their heads towards the sound and watched as a young boy stood in the doorway. He was short, with messy brown hair and a slim figure. He bore a smaller version of the Monastery’s uniform and was visibly nervous as he fidgeted in place.

“May I...come in?” he turned his large, hazel eyes to Byleth who he recognised as his professor.

Byleth’s heart skipped a beat as the boy stared at her with such an innocent expression. He was adorable, an almost visual manifestation of childhood innocence. Byleth gulped, but regained her composure as she asked the boy to introduce himself to the class.

“Um, my name is Lukas! I hope we can all get along!” The boy introduced himself before rushing to a seat far away from the rest of his peers.

“Aw, cutie!” Dorothea whispered to Edelgard. 

“He is certainly...cute.” Edelgard reaffirmed Dorothea’s comment.

Byleth continued with her lesson for the day, ignoring the aching in her body whenever she glanced over at Lukas. The young boy was clearly eager to learn, he was exceptionally engaged with the lesson even though it was far beyond what his years should allow. This just added to his charm to Byleth, whenever he raised his hand to answer a question her heart raced. She was sure to heap praise on him whenever he got a question right which happened so often it started to make the other students feel a little bit jealous. Lukas was a perfect student, and there was nothing Byleth loved more than a perfect student.

* * *

Lukas had soon settled into the Monastery, a popular figure especially among the female students who found him adorable. Due to his age however, Lukas found it difficult to relate to his teenage peers. He often overheard them talking about odd things, especially Sylvain, alien slang and descriptions of acts he didn’t understand. It made him feel like a baby not understanding what his classmates were talking about. 

One evening, while diligently studying in the library, playfully kicking his legs under the table he sat on while buried in his book, Lukas overheard two male students whispering between each other near him.

“Hey, it’s Annette, isn’t she cute?” One of the students said to his friend. Lukas observed as Annette indeed entered the library.

“Yeah, she’s cute, but not as cute as Mercedes!”

Lukas felt rude eavesdropping on their conversation but for some reason continued to listen intently. 

“Mercedes isn’t cute, she’s  _ hot _ !” The student snickered to his friend.

Lukas’s face flushed as he heard the exaggerated ‘hot’ hiss out of the students' lips. Is this what older boys really spoke about? Lukas would never talk about his female peers like that! 

“No way, I’ll tell you who’s hot; Professor Byleth. Man, her tits drive me crazy sometimes!”

Lukas almost let out an audible gasp. He was confused. They were talking about his professors...tits? What were those? He could understand where they were coming from though, Byleth was beautiful. Lukas could spend hours staring at her during her lectures, his eyes roaming her figure. It gave him a foreign sensation, a tight feeling in his stomach when he did. For some reason his eyes were just drawn to Byleth, sometimes not even taking in what she’s saying during these moments. 

Lukas shut his book promptly and returned it where it had come from neatly. He quietly left the library, walking in the direction of the dorms with intent. 

* * *

It was late evening, classes had ended and Byleth sat alone in her room, marking papers from the day's lesson. She perked up when she heard a soft knocking at her door, to which she got up from her desk and opened her dorm door. Lukas stood in her doorway, his face red and his hands fidgeting in front of him.

“Good evening, Professor-” Lukas mumbled. “May I come in?”

Byleth was more than happy to let her student in. She stepped to the side and held her hand out in welcome. Lukas stood awkwardly in the middle of the room between Byleth’s desk and bed, his eyes darting around. Being in his professors bedroom made that odd, tight feeling come back. 

“How can I help you?” Byleth asked.

“Um-! Professor...what are tits?” Lukas sputtered. “I keep hearing people around the Monastery say it but...what does it mean?”

Byleth stared at the boy, her cheeks turning a delicate shade of pink. 

“Lukas, who did you hear say those words?” 

“I don’t know! Some boys in the library!” Lukas squeaked. 

“I see...Lukas that’s a word a boy like you should not be using, understand?” Byleth said firmly.

“I’m not using it!” Lukas defended himself. “I’m annoyed I don’t know what those kinds of words mean when all the other students do.” The boy sniffled into his sleeve. 

Byleth felt sympathy for Lukas. He was surrounded by students much older than him, practically in a completely separate world due to his prepubescent state. She got on her knees and pulled Lukas in for a tight hug to comfort him, stroking his soft hair lovingly as he returned the embrace. 

“Don’t be so eager to grow up, understand?” Byleth whispered into his ear.

“Okay...thank you.” Lukas whimpered. The tight feeling intensified as Byleth continued to hug him. Eventually, Byleth felt something poke against her figure. She pulled away and looked down to see a small protrusion from Lukas’s pants. 

“Professor...what's wrong?” Lukas asked.

Byleths mouth was agape. Her image of Lukas, as a cute innocent boy she was unfairly preying on, all the guilt she had felt for heating up in his presence, melted away instantly. Lukas was getting an erection from being close to her. 

“Lukas...as long as you don’t tell anyone, I’ll tell you what ‘tits’ means.” Byleth offered to the young boy.

“Yes please, Professor!” Lukas beamed at his professor, completely unaware of her fascination with his crotch.

Byleth instructed Lukas to cover his eyes. He did so, his small hands covering his face as Byleth undressed in front of him. She took her time, allowing herself to become aroused at the idea that she was exposing herself to Lukas without his knowledge. Eventually, Byleth’s shirt was off, exposing her large, soft, breasts.

“Okay...open your eyes.” Byleth said.

Lukas did so and immediately let out a shocked gasp. He placed his hands on his red cheeks, his eyes fixated on the large mammaries in front of him. 

“Professor, what are you doing?!” He said, still unable to take his eyes off of his professor’s exposed chest.

“These-” Byleth grabbed both her breasts and pushed them towards Lukas’s face. “Are tits.” 

“I see-!” Lukas’s voice was muffled by the fleshy orbs being smothered in his face. He reached out to push them away instinctively, causing a lewd moan from Byleth. “Sorry, Professor! Did that hurt?”

“No, it’s okay.” Byleth sighed. “It feels good when you touch them.” Byleth reached out and held onto Lukas’s hands, guiding him to her breasts and encouraging him to feel them. Lukas, quick learner that he was, soon got into the rhythm of groping and pulling them in ways that pleased Byleth. He couldn’t take his young eyes off of Byleth’s chest, the size and softness of them bringing out some sort of instinct in the boy. He just wanted to touch them and squeeze them forever, kneading and pawing until he couldn’t any longer.

Byleth watched in joy as her young student played with her body. She placed a hand on his head and pet him gently.

“You’re making me feel really good, Lukas.” She whined.

“I...am?” Lukas said in his dazed state.

“Do you want to make me feel even better?” Byleth asked.

Lukas looked up at her with wide eyes and nodded eagerly. 

* * *

Sat upright on her bed only in her panties, Byleth ran her thighs across Lukas’s cheeks gently. His face was intimately close to her crotch, his head almost completely obscured from Byleth’s perspective. 

“Now...Pull my panties to the side.” Byleth ordered. 

Lukas obeyed his professor, pulling her lace black panties to the side exposing her sex to him. His eyes widened as he saw it, a sort of figure he had seen his biology books surrounded by soft, dark pubic hair. 

“Put your tongue here-” Byleth pinched her clit between two fingers. “And lick it, okay?”

Lukas did as he was told, placing his small soft tongue on Byleth’s clit. He licked gently, the room echoing with the noises of his lapping. Byleth watched in twisted perversion as her favorite pupil was eating her out, a cute innocent boy being corrupted by her hands. A perverse smile ran across her face, her moans beginning to escape her mouth as she groped at her chest.

“That’s good, why don’t you go a little faster?” She huffed.

Without a word, Lukas obeyed his orders. His licking became a lot more frantic, a reflection of his own arousal, though he was still unsure what the feeling inside him was. For some reason, his underwear felt a lot tighter, his mind hazier and his affection for Byleth ever growing as her lewd noises filled her dorm room. Out of instinct, his hips started to buck every so often as he continued to lick Byleth. Byleth noticed this and chuckled softly.

“Excited, are we? Cute.” Byleth’s own hips started to roll, the sight of her adorable student becoming fervent with excitement assisting her arousal as well as her ever approaching orgasm.

She felt it coming, an ever approaching rush of bliss that her student was bringing closer and closer. Was she really going to cum on her young student? She didn’t have time to ponder the morality of her actions as her back arched and she cried out as a flood of her juices covered Lukas’s face, leaking down his chin. 

After a moment, Lukas peered up from his spot between Byleth’s thighs. He looked at his professor, eagerly awaiting approval. 

“Good boy…” Byleth huffed. She slowly slid onto her back, her eyes fluttering as she regained her energy from her intense orgasm.

Lukas rubbed his face with his sleeve. His professor seemed happy, but the boy was dissatisfied. Without thinking, he pulled down his shorts and underwear, releasing his three inch prick from its confines. He crawled on top of his professor's almost unconscious body and squeezed her breasts to form a small opening as he sat just above her stomach. Byleth opened her eyes and watched as Lukas slid his erection between her breasts, wildly humping them. Byleth’s breasts were so large they completely enveloped the boys less than average dick but this just made it feel even better for Lukas.

“Lukas! What are you doing?!” Byleth sounded angry, but in reality she was pleasantly surprised with Lukas’s initiative. 

“Sorry, Professor! But...my thingie! It feels weird!” Lukas whined, the sound of flesh against flesh as he continued to thrust as hard and as fast as he could. 

“Lukas…!” Byleth growled. She grabbed the boy by the hips and effortlessly lifted him off of her. Lukas looked at her with puppy dog eyes, his fun ending far too soon. “Ask permission before doing that kind of thing!”

“Sorry...I just don’t understand what’s going on...down there.” Lukas motioned to his still hard cock.

“I guess there’s no helping it…” Byleth sighed. She gently placed the boy on her bed, his head resting against the pillow as Byleth hovered above him, her sex just above his erection.

“Professor…? What are you doing?” Lukas asked innocently.

He received no answer. Instead he watched as his professor, the teacher he admired and loved so much, lowered herself onto his young cock, taking his virginity. Lukas whined, the warmth and tightness of Byleth’s cunt completely taking him aback. He dug his fingers into the bed sheets and panted and moaned as Byleth began to ride him. 

“Professor, what is this!?” He could barely get his words out. 

Byleth didn’t respond. Too lost in her perversion, she continued to drive her hips up and down on Lukas’s dick, her round ass bouncing as she did. Despite Lukas’s less than average size, the idea of doing something so depraved was more than enough to get Byleth off. Her pleasure came not from the act, but knowing she was doing something so sinful. She admired Lukas’s flushed face, his cute innocent eyes staring up at her and his soft hair roughed up. His childish face was coated in sweat, an expression someone of his age should not be bearing. Yet here he was, copulating with his older professor. 

“Next time you hear students talk about me…” Byleth said in between her moans. “How much they want to fuck me, how much they love my body; remember this.” She leaned down and gave Lukas a wet, sloppy kiss. “You’ve gotten more than they ever will.”

Lukas was content. He truly felt like his professor's favorite. He allowed her to follow into her second orgasm, her hole tightening around his cock causing him to release his watery cum into her. 

“Professor...what just happened? It felt like I...peed.” Lukas could barely get his words out in his exhaustion. 

Placing another kiss on his lips, Byleth smiled.

“I’ll tell you when you’re older.”

* * *

Byleth lay in her bed, the moon and the stars creating the only light source in her room. In her arms was Lukas who was gently snoring with his face planted in Byelth’s chest. The young boy, in his fatigue, had fallen asleep in Byleth’s room. Not having the heart to kick him out, Byleth chose not to wake him and instead allow him to stay the night. 

“Seriously?” A voice abruptly spoke up from the corner of the room. “What is wrong with you?” Sothis looked at Byleth with an angry expression.

Byleth flashed her friend a warm smile, before turning her attention back to her sleeping student. Stroking his hair, her eyes began to feel heavy as she drifted off to sleep


End file.
